A series of studies are designed to determine the therapeutic value of specific and non-specific immunostimulants after tumor burden has been reduced with chemotherapy, surgery, or radiation. Tumor cells selected by drugs, membrane properties, and propensity for various metastatic sites are modified with neuraminidase and used as specific immunostimulants. BCG and reovirus serve as non-specific immunostimulants. The dose, route, and frequency of administration of immunostimulants is being evaluated as a function of time after primary therapy. Various parameters of cellular and humoral immunity are measured during the course of therapy to determine if there are correlations between these parameters and successful therapy. These studies are being conducted on mice with transplantable leukemia, lymphoma, and breast tumor. BIBLIOGRAPHIC REFERENCES: Kollmorgen, G.M., J.J. Killion, W.A. Sansing, and J.C. Bundren, Combination chemotherapy and immunotherapy of transplantable murine leukemia, in The Cell Cycle in Malignancy and Immunity. (1975). Sansing, W.A., J.L. Cantrell, J.J. Killion, and G.M. Kollmorgen, The role of thymic cells in the L1210-BDF1 tumor-host system. In Vitro 10: 368, (1975).